Various coatings are sometimes applied to the inner surface of pneumatic tires for various purposes. For example, sealant compositions are sometimes applied to the inner surface of cured pneumatic tires by spray coating or by applying strips of sealant composition.
A difficulty is readily experienced in the application of such inner coatings caused primarily by the manufacturing process for the pneumatic tire itself. For example, after building a greenc unvulcanized tire, its inner surface is conventionally coated with a release material. Such inner release coat is provided for the purpose of preventing the inner surface of the pneumatic tire from sticking to the pneumatic shaping bladder in its molding and curing process.
If it is desired to apply a coating, such as a puncrure sealant, to the inner surface of the cured pneumatic tire, it is normally required that the previously applied inner release coat be removed prior to application of the sealant coat. Otherwise, the application of such sealant coat will normally not effectively adhere to the tire's inner surface because of the presence of the release agent coat. Consequently, the removal of such release agent coat is typically required before the application of such additional coat.
The removal process for the release coat can include a soap-wash, a buffing or abrading of the surface or a combination of such processes. Such processes are additive steps in the preparation of a tire and can add an appreciable cost to the finished tire.
Therefore, it is a purpose of this invention to provide a means for preparing a cured pneumatic rubber tire which has an inner surface to which can conveniently be applied an internal coating such as a sealant.